1. Field of the Invention
The present invention relates to a method for the quality control of material layers. Methods of this type are used in particular in quality control and quality assurance of articles which can be mass-produced.
2. Description of the Related Art
According to WO 98/18135, the quality of a coating is checked by light being radiated onto the coating and the transmitted light being detected. From the transmission or respectively the absorption of the light as it passes through the coating, conclusions are made about local or overall defects in the coating.
U.S. Pat. No. 4,302,108 discloses a method in which a coating is also scanned with a light beam. What is crucial here is that the angle of radiation onto the coating is so selected that at least a portion of the beam is reflected. The intensity of the reflected beam is then detected in order to determine surface anomalies of the structure. By means of this method, which is substantially based on an angle of radiation which leads to a reflection at the surface of the coating, surface defects of the coating can be detected. These described methods relate to planar surfaces.